US7333309B2 - Self field triggered superconducting fault current limiter - Google Patents
Self field triggered superconducting fault current limiter Download PDFInfo
- Publication number
- US7333309B2 US7333309B2 US11/436,869 US43686906A US7333309B2 US 7333309 B2 US7333309 B2 US 7333309B2 US 43686906 A US43686906 A US 43686906A US 7333309 B2 US7333309 B2 US 7333309B2
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- US
- United States
- Prior art keywords
- superconductor
- fault current
- array
- current limiter
- elements
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- Legal status (The legal status is an assumption and is not a legal conclusion. Google has not performed a legal analysis and makes no representation as to the accuracy of the status listed.)
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- H—ELECTRICITY
- H01—ELECTRIC ELEMENTS
- H01F—MAGNETS; INDUCTANCES; TRANSFORMERS; SELECTION OF MATERIALS FOR THEIR MAGNETIC PROPERTIES
- H01F6/00—Superconducting magnets; Superconducting coils
-
- H—ELECTRICITY
- H02—GENERATION; CONVERSION OR DISTRIBUTION OF ELECTRIC POWER
- H02H—EMERGENCY PROTECTIVE CIRCUIT ARRANGEMENTS
- H02H9/00—Emergency protective circuit arrangements for limiting excess current or voltage without disconnection
- H02H9/02—Emergency protective circuit arrangements for limiting excess current or voltage without disconnection responsive to excess current
- H02H9/023—Current limitation using superconducting elements
-
- H—ELECTRICITY
- H01—ELECTRIC ELEMENTS
- H01F—MAGNETS; INDUCTANCES; TRANSFORMERS; SELECTION OF MATERIALS FOR THEIR MAGNETIC PROPERTIES
- H01F6/00—Superconducting magnets; Superconducting coils
- H01F2006/001—Constructive details of inductive current limiters
-
- Y—GENERAL TAGGING OF NEW TECHNOLOGICAL DEVELOPMENTS; GENERAL TAGGING OF CROSS-SECTIONAL TECHNOLOGIES SPANNING OVER SEVERAL SECTIONS OF THE IPC; TECHNICAL SUBJECTS COVERED BY FORMER USPC CROSS-REFERENCE ART COLLECTIONS [XRACs] AND DIGESTS
- Y02—TECHNOLOGIES OR APPLICATIONS FOR MITIGATION OR ADAPTATION AGAINST CLIMATE CHANGE
- Y02E—REDUCTION OF GREENHOUSE GAS [GHG] EMISSIONS, RELATED TO ENERGY GENERATION, TRANSMISSION OR DISTRIBUTION
- Y02E40/00—Technologies for an efficient electrical power generation, transmission or distribution
- Y02E40/60—Superconducting electric elements or equipment; Power systems integrating superconducting elements or equipment
Definitions
- the invention relates generally to a current limiter and more specifically to a superconducting fault current limiter.
- Superconductors especially high-temperature superconducting (HTS) materials, are well suited for use in a current limiting device because of their intrinsic properties that can be manipulated to achieve the effect of “variable impedance” under certain operating conditions.
- a superconductor when operated within a certain temperature and external magnetic field range (i.e., the “critical temperature” (T c ) and “critical magnetic field” (H c ) range), exhibits no electrical resistance if the current flowing through it is below a certain threshold (i.e., the “critical current level” (J c )), and is therefore said to be in a “superconducting state.” However, if the current exceeds this critical current level the superconductor will undergo a transition from its superconducting state to a “normal resistive state.” This transition of a superconductor from its superconducting state to a normal resistive state is termed “quenching.” Quenching can occur if any one or any combination of the three factors, namely the operating temperature,
- a superconductor once quenched, can be brought back to its superconducting state by changing the operating environment to within the boundary of its critical current, critical temperature and critical magnetic field range, provided that no thermal or structural damage was done during the quenching of the superconductor.
- HTS material can operate near the liquid nitrogen temperature 77 degrees Kelvin (77K) as compared with low-temperature superconducting (LTS) material that operates near liquid helium temperature (4K). Manipulating properties of HTS material is much easier because of its higher and broader operating temperature range.
- HTS materials such as BSCCO, YBCO, or MgB 2 elements
- non-uniform regions can develop into the so-called “hot spots” during the surge of current that exceeds the critical current level of the superconductor.
- a resistive region will generate heat from its associated i 2 r loss. If the heat generated could not be propagated to its surrounding regions and environment quickly enough, the localized heating will damage the superconductor and could lead to the breakdown (burn-out) of the entire superconductor element.
- a magnetic field is used to trigger HTS materials to improve speed and uniform quenching during transition from superconducting to normal resistive state.
- SCFCL Superconducting Fault Current Limiter
- US Publication US2005/0099253A1 published on May 12, 2005, discloses a superconducting current limiting device comprising a superconductor body electrically connected in parallel with a shunt coil wherein the shunt coil is in tight contact with the external surface of the superconducting body.
- the shunt coil has an external shape to allow a circular current to flow. This publication does not disclose or teach the elimination of the external shunt coil to use other means for generating a magnetic field to assist in quenching.
- U.S. Pat. No. 6,043,731 discloses a current limiting device having a superconductor, a shunt coil wrapped around the superconductor and connected in parallel with the superconductor, wherein the shunt coil generates a magnetic field to assist in quenching the superconductor.
- the shunt coil is controlled by active means.
- This patent does not disclose or teach the elimination of the external shunt coil to use other means for generating a magnetic field to assist in quenching.
- a superconducting fault current limiter array has a plurality of superconductor elements arranged in a meandering array that has the respective shape of a circle, ellipse, or a rectangle.
- the meandering array has an even number of superconductors substantially parallel to each other and arranged in a plane that is generally parallel to an odd number of superconductors, where the odd number of superconductors are substantially parallel to each other and arranged in a plane that is generally parallel to the even number of superconductors, when viewed from a top view.
- the even number of superconductors are coupled at the upper end to the upper end of said odd number of superconductors.
- a series array superconducting fault current limiter is configured to have at least two modules, wherein each module electrically coupled in series with each other module.
- the modular nature of the superconducting fault current limiter makes it very desirable in high voltage and/or high current environments of the power system to which it connects.
- a fault current limiter array has a plurality of superconductors each superconductor having upper and lower ends, a plurality of upper and lower shunt coils, wherein the plurality of superconductors is arranged in a line, having superconductors parallel to each other and arranged in adjacent pairs, a plurality of upper shunt coils each coil electrically coupled to every other pair of superconductors at a respective upper end.
- the lower end of the other pairs of superconductors is electrically coupled together and a plurality of lower shunt coils each coil electrically coupled to every other pair of superconductors at a respective lower end, wherein the upper end of every other pair of superconductors is electrically coupled together.
- the line of superconducting element are disposed substantially parallel to each other in a plane so that the electromagnetic force generated by each superconductor magnetic field is minimized and does not introduce mechanical stress on the respective individual superconductor.
- FIG. 1 illustrates a simplified physical component layout of a basic self field triggered fault current limiter of the present invention.
- FIG. 2 illustrates a side view from plane 2 - 2 of FIG. 1 of the self field triggered fault current limiter of the present invention.
- FIG. 3 illustrates an top view from plane 3 - 3 of FIG. 1 of the self field triggered fault current limiter of the present invention.
- FIG. 4 illustrates an equivalent electrical schematic circuit of the self field triggered fault current limiter of the present invention.
- FIG. 5 illustrates multiple shunt coils on a single former having tapped windings of the present invention.
- FIG. 6 illustrates modules arranged to produce a low magnetic field between sections of the present invention.
- FIG. 7 illustrates modules arranged to produce high magnetic field between sections of the present invention.
- FIG. 8 illustrates a simplified self field triggered fault current limiter of the present invention.
- FIG. 9 illustrates a top view of FIG. 8 of the present invention.
- FIG. 10 illustrates an equivalent circuit of the present invention of FIG. 8 having top and bottom shunt impedances.
- FIG. 11 illustrates an equivalent circuit of the present invention of FIG. 8 with a single side of shunt impedances.
- FIG. 12 illustrates alternative embodiments of the top view from plane 3 - 3 of FIG. 1 , of the self field fault current limiter of the present invention.
- This invention provides an approach to generate the magnetic field from the HTS elements themselves.
- This invention also employs shunt coils to protect HTS elements from uncontrolled energy input during fault limiting conditions.
- the shunt coils also help to reduce the effect of statistical variations of HTS elements.
- the superconducting fault current limiter (SCFCL) array uses a magnetic field generated by the superconductor elements for self triggering. This approach eliminates the need for external magnetic field generating coils or windings and makes the design of SCFCL less complex.
- Superconducting elements including rods, tubes, tapes or wires made of single superconductor elements or multiple superconductor elements connected in series or parallel, arranged in a way to form a rectangular, oval or circular winding and produce a net magnetic field common to all elements.
- the design has low magnetic field and low inductive/resistive impedance.
- the magnetic field will be high enough to influence the critical current density of the superconductor material and help to quench uniformly and quickly.
- the arrangement provides a net magnetic field higher than the self field of each superconductor element, which provides a design as simple as a series resistive SCFCL with an added advantage of having a trigger magnetic field.
- Each superconductor element is protected against excessive energy dump by a shunt impedance.
- the shunt impedance protects a single superconductor element or staggered superconductor elements to protect multiple elements. Using such a configuration, one shunt coil at the associated impedance protects multiple elements and help to improve the protection system and further reduces the statistical variation of quenching speed and voltage development among superconductor elements.
- FIG. 1 illustrates the fault current limiter array 10 of the present invention and is arranged to form a rectangular, oval or circular winding to produce a net magnetic field 6 common to all superconductor elements.
- Fault current limiter 10 has a plurality of superconductor elements sc 1 to sc n disposed in a “meandering” arrangement.
- FIG. 3 as viewed from the top defined by cross hatch 3 - 3 , illustrates the arrangement of the superconductors sc 1 to sc n .
- Each superconductor is arranged in a zigzag wherein an even number of superconductors sc 2 , sc 4 , sc n-1 , are substantially parallel to each other and disposed in a plane that is generally parallel to the odd number of superconductors sc 1 , sc 3 , . . . sc n ., wherein the odd number of superconductors are substantially parallel to each other also.
- a plurality of odd shunt coils r a1 to r an are electrically connected to the upper end of the odd number of superconductors.
- a plurality of even shunt coils r b1 to r bn are electrically connected to the even number of superconductors.
- Cross hatch 2 - 2 is a cross section of array 10 , as viewed from either side, and is illustrated in FIG. 2 .
- FIG. 3 shows meandering array 10 that is generally arranged in a straight line, it is understood that this line merely illustrates a portion of a much larger meandering array 10 made of single superconductor elements or multiple superconductor elements connected in series or parallel, arranged in a way to form a rectangular, elliptical or circular winding and produce a net magnetic field common to all elements, as illustrated in FIG. 12 .
- the superconductors sc 1 . . . sc n all have low magnetic field and low impedance.
- the magnetic field 6 is high enough to influence the critical current density of the superconductor material and help the superconductor quench uniformly and quickly.
- the arrangement provides a net magnetic field higher than the self field of each superconductor element, which provides a design as simple as a series resistive fault current limiter with an added advantage of having a trigger magnetic field.
- Each superconductor element sc 1 . . . sc n is protected against excessive energy dump by shunt impedance r a1-an and r b1-bn .
- the shunt impedance protects an associated single superconductor element sc or staggered superconductors to protect multiple elements.
- the impedance of one shunt coil protects multiple superconductor elements and helps to improve the protection system and reduces the statistical variation of quenching speed and voltage development among superconductor elements.
- FIG. 5 shows the design of the shunt coil impedance r a1-an or r b1-bn respectively.
- the two groups of shunt coils shown in FIG. 1 may be produced with two single formers with a shunt impedance between conductors taken from tapped terminals.
- the respective shunt coils r a1 . . . an or r b1 . . . bn can be a single or multi-layer windings wound on formers of circular, rectangular, elliptical or a combination of these shapes convenient for the design of the required impedance.
- Using a single former for half of the shunt coils per module reduces the number of individual shunt coils to be wound and also improves the electrical and mechanical designs.
- FIGS. 6 and 7 shows how such SCFCL arrays or modules are arranged to employ magnetic field 6 arrangements to generate regions between modules that have a low 18 or high 20 magnetic field.
- the fault current limiter response time and quenching performance will have to be selected based on the sensitivity of the HTS material to the magnetic field orientation, either in parallel or perpendicular to the HTS.
- FIG. 6 shows an example of assembly from modules. Note that shunt coils, which are not shown in FIG. 6 are still part of the system. Depending on the applications and the required magnetic field level, the field region between sections or modules can be low 18 as illustrated in FIG. 6 or high 20 as illustrated in FIG. 7 . Such flexibility will give more freedom in selecting arrays to withstand mechanical stresses from the short circuit forces.
- FIG. 6 and FIG. 7 show how such sections or modules are connected in series in order to configure for low or high magnetic field designs.
- current “I” 14 enters at sc 1 and exits sc n of a first array and is electrically coupled to sc 1 of a second array.
- the current “I” 16 exits the second array at sc n .
- High voltage design consideration is also one of the primary drivers for such a simplified design concept.
- Reduced or no external magnetic field coils means a simple resistive network with improved uniform voltage distribution for both lightning impulse and AC applications.
- the overall fault current limiter design can be simplified to a matrix of modules with HTS elements arranged in another type of meandering arrangement with shunt windings/impedances arranged along the HTS contact terminals, so that the magnetic field produced by the current through the HTS elements and connector terminals does not induce voltage in the shunt coils, hence eliminate or minimize the power loss in the shunt coils and reduce the overall cooling power requirements during normal operation and minimizes electromagnetic interference between main HTS current and shunt coils.
- FIGS. 8 to FIG. 11 Such a simplified version of the main fault current limiter, which relies on the self magnetic field of each individual HTS element is shown in FIGS. 8 to FIG. 11 . This simplified version helps to reduce the overall inductance of
- the design is simplified by providing one shunt coil r a1 , either connected to the top of superconductor pair sc 1 and sc 2 or bottom, for two superconducting elements and further reduce the number of components, which helps in improved manufacturability and better reliability.
- the adjacent superconductor pair sc 3 and sc 4 is arranged in an opposite configuration wherein the shunt coil r b1 is connected to the opposite end as r a1 and the other (top) end of sc 2 and sc 3 is electrically coupled together.
- the alternating connection approach is repeated for each of the superconductor pairs until sc n is coupled in the array, where current “I” enters at 14 and exits at 16 .
- FIG. 9 illustrates the same connection arrangement as described in FIG. 8 but from a top view.
- FIG. 10 shows the equivalent electrical schematic of the invention in FIG. 8 .
- FIG. 11 illustrates an alternative embodiment of the equivalent circuit illustrated in FIG. 10 .
- a respective r c1 . . . n replaces the equivalent impedance of a respective r a1 . . . an and r b1 . . . bn has been eliminated.
- the shunt coils r a1 . . . an and r b1 . . . bn in the present invention are made of electrically conductive materials and in configurations that are selected from the group including helically-wound solenoid coils, racetrack coils, and saddle coils wound on a rectangular or circular or oval former.
- the superconductors sc 1 . . . n in either non-inductive and alternatively low-inductive form in the present invention, are selected from the group including rods, bars, plates, tape strips, wires, tubes, and bifilar coils which can be a single superconductor or multiple superconductor elements in series or parallel connections with a single or multi-layer windings.
- the present invention provides for a less complex fault current limiter design in high voltage electrical power system applications.
- This invention uses a self magnetic field for uniform quenching and fast transition from superconducting to normal (resistive) state and yet lends itself for simplified design for high voltage, mechanical, electrical and electromagnetic design applications.
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- Containers, Films, And Cooling For Superconductive Devices (AREA)
Abstract
Description
for n multiple coils on a single former when using superconductors that are sensitive to the orientation (direction) of the magnetic field, the design and arrangement of the superconductor elements sc and shunt coils ra and rb will have to take into account both the magnitude and direction of the magnetic field. Such sections or modules with superconductor elements and shunt coils can be arranged or placed with another section to enhance the magnetic field and also to improve uniformity of the magnetic field.
Claims (18)
Priority Applications (2)
Application Number | Priority Date | Filing Date | Title |
---|---|---|---|
US11/436,869 US7333309B2 (en) | 2005-06-02 | 2006-05-18 | Self field triggered superconducting fault current limiter |
PCT/US2006/020939 WO2008045013A2 (en) | 2005-06-02 | 2006-05-30 | Self field triggered superconducting fault current limiter |
Applications Claiming Priority (2)
Application Number | Priority Date | Filing Date | Title |
---|---|---|---|
US68676405P | 2005-06-02 | 2005-06-02 | |
US11/436,869 US7333309B2 (en) | 2005-06-02 | 2006-05-18 | Self field triggered superconducting fault current limiter |
Publications (2)
Publication Number | Publication Date |
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US20060279388A1 US20060279388A1 (en) | 2006-12-14 |
US7333309B2 true US7333309B2 (en) | 2008-02-19 |
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US11/436,869 Expired - Fee Related US7333309B2 (en) | 2005-06-02 | 2006-05-18 | Self field triggered superconducting fault current limiter |
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US (1) | US7333309B2 (en) |
WO (1) | WO2008045013A2 (en) |
Cited By (1)
Publication number | Priority date | Publication date | Assignee | Title |
---|---|---|---|---|
US20110177953A1 (en) * | 2010-01-21 | 2011-07-21 | Superpower, Inc. | Superconducting fault current-limiter with variable shunt impedance |
Families Citing this family (4)
Publication number | Priority date | Publication date | Assignee | Title |
---|---|---|---|---|
US20090156409A1 (en) * | 2007-12-17 | 2009-06-18 | Superpower, Inc. | Fault current limiter incorporating a superconducting article |
GB201801604D0 (en) * | 2018-01-31 | 2018-03-14 | Tokamak Energy Ltd | magnetic quench induction system |
DE102018211511A1 (en) * | 2018-07-11 | 2020-01-16 | Bruker Biospin Gmbh | Superconducting magnetic coil system |
US11380731B1 (en) * | 2019-09-26 | 2022-07-05 | PsiQuantum Corp. | Superconducting device with asymmetric impedance |
Citations (6)
Publication number | Priority date | Publication date | Assignee | Title |
---|---|---|---|---|
US5361055A (en) * | 1993-12-17 | 1994-11-01 | General Dynamics Corporation | Persistent protective switch for superconductive magnets |
US6043731A (en) | 1995-03-24 | 2000-03-28 | Oxford Instruments Plc | Current limiting device |
US6137388A (en) | 1997-03-19 | 2000-10-24 | Va Tech Elin Service B.V. | Resistive superconducting current limiter |
US6664875B2 (en) | 2001-01-17 | 2003-12-16 | Igc-Superpower, Llc | Matrix-type superconducting fault current limiter |
US6809910B1 (en) | 2003-06-26 | 2004-10-26 | Superpower, Inc. | Method and apparatus to trigger superconductors in current limiting devices |
US20050099253A1 (en) | 2003-10-15 | 2005-05-12 | Joachim Bock | Superconducting current limiting device with magnetic field assisted quenching |
-
2006
- 2006-05-18 US US11/436,869 patent/US7333309B2/en not_active Expired - Fee Related
- 2006-05-30 WO PCT/US2006/020939 patent/WO2008045013A2/en active Application Filing
Patent Citations (6)
Publication number | Priority date | Publication date | Assignee | Title |
---|---|---|---|---|
US5361055A (en) * | 1993-12-17 | 1994-11-01 | General Dynamics Corporation | Persistent protective switch for superconductive magnets |
US6043731A (en) | 1995-03-24 | 2000-03-28 | Oxford Instruments Plc | Current limiting device |
US6137388A (en) | 1997-03-19 | 2000-10-24 | Va Tech Elin Service B.V. | Resistive superconducting current limiter |
US6664875B2 (en) | 2001-01-17 | 2003-12-16 | Igc-Superpower, Llc | Matrix-type superconducting fault current limiter |
US6809910B1 (en) | 2003-06-26 | 2004-10-26 | Superpower, Inc. | Method and apparatus to trigger superconductors in current limiting devices |
US20050099253A1 (en) | 2003-10-15 | 2005-05-12 | Joachim Bock | Superconducting current limiting device with magnetic field assisted quenching |
Cited By (2)
Publication number | Priority date | Publication date | Assignee | Title |
---|---|---|---|---|
US20110177953A1 (en) * | 2010-01-21 | 2011-07-21 | Superpower, Inc. | Superconducting fault current-limiter with variable shunt impedance |
US8588875B2 (en) | 2010-01-21 | 2013-11-19 | Superpower, Inc. | Superconducting fault current-limiter with variable shunt impedance |
Also Published As
Publication number | Publication date |
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US20060279388A1 (en) | 2006-12-14 |
WO2008045013A2 (en) | 2008-04-17 |
WO2008045013A3 (en) | 2008-10-23 |
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